package com.tianji.learning.service.impl;

import cn.hutool.db.DbRuntimeException;
import com.tianji.api.client.course.CourseClient;
import com.tianji.api.dto.course.CourseFullInfoDTO;
import com.tianji.api.dto.leanring.LearningLessonDTO;
import com.tianji.api.dto.leanring.LearningRecordDTO;
import com.tianji.common.exceptions.BizIllegalException;
import com.tianji.common.exceptions.DbException;
import com.tianji.common.utils.BeanUtils;
import com.tianji.common.utils.UserContext;
import com.tianji.learning.domain.dto.LearningRecordFormDTO;
import com.tianji.learning.domain.po.LearningLesson;
import com.tianji.learning.domain.po.LearningRecord;
import com.tianji.learning.enums.LessonStatus;
import com.tianji.learning.enums.SectionType;
import com.tianji.learning.mapper.LearningRecordMapper;
import com.tianji.learning.service.ILearningLessonService;
import com.tianji.learning.service.ILearningRecordService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.tianji.learning.utils.LearningRecordDelayTaskHandler;
import lombok.RequiredArgsConstructor;
import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Service;

import java.util.List;

/**
 * <p>
 * 学习记录表 服务实现类
 * </p>
 *
 * @author LYY
 * @since 2025-05-10
 */
@Service
@RequiredArgsConstructor
@Slf4j
public class LearningRecordServiceImpl extends ServiceImpl<LearningRecordMapper, LearningRecord> implements ILearningRecordService {
    private final ILearningLessonService lessonService;
    private final CourseClient courseClient;
private final LearningRecordDelayTaskHandler taskHandler;
    @Override
    public LearningLessonDTO queryLearningRecordByCourse(Long courseId) {
        //获取当前登录id
        Long userId = UserContext.getUser();
        //查询课表信息  条件是userid和courseid
        LearningLesson lesson = lessonService.lambdaQuery()
                .eq(LearningLesson::getUserId, userId)
                .eq(LearningLesson::getCourseId, courseId)
                .one();
        if (lesson == null) {
            throw new BizIllegalException("该课程未加入课表");
        }
        //查询记录 条件lessonid userid
        List<LearningRecord> recordList = this.lambdaQuery()
                .eq(LearningRecord::getLessonId, lesson.getId())
                .eq(LearningRecord::getUserId, userId)
                .list();
        //封装结果返回
        LearningLessonDTO dto = new LearningLessonDTO();
        dto.setId(lesson.getId());
        dto.setLatestSectionId(lesson.getLatestSectionId());
        List<LearningRecordDTO> dtoList = BeanUtils.copyList(recordList, LearningRecordDTO.class);
        dto.setRecords(dtoList);

        return dto;
    }

    /**
     * 提交学习记录
     *
     * @param dto
     */
    @Override
    public void addLearningRecord(LearningRecordFormDTO dto) {
        // 查询当前登录用户的id
        Long userId = UserContext.getUser();
        // 处理学习记录
        boolean isFinished = false;// 代表本小节是否已学完
        if (dto.getSectionType().equals(SectionType.VIDEO)) {
            // 提交视频播放记录
            isFinished = handleVideoRecord(userId, dto);
        } else {
            // 提交考试记录
            isFinished = handleExamRecord(userId, dto);
        }
        // 处理课表数据
        if (!isFinished) {// 如果本小节不是第一次学完 不用处理课表数据
            return;
        }
        handleLessonData(dto);
    }

    // 处理课表相关数据
    private void handleLessonData(LearningRecordFormDTO dto) {
        // 查询课表数据 learning_lesson  条件 主键id
        LearningLesson lesson = lessonService.getById(dto.getLessonId());
        if (lesson == null) {
            throw new BizIllegalException("课表不存在");
        }
        // 判断是否是第一次学完 isFinished是不是true
        boolean allFinished = false;
        // 远程调用课程服务 得到课程信息 总小节数
        CourseFullInfoDTO cinfo = courseClient.getCourseInfoById(lesson.getCourseId(), false, false);
        if (cinfo == null) {
            throw new BizIllegalException("课程不存在");
        }
        Integer sectionNum = cinfo.getSectionNum();// 该课程下小节总数
        // isFinished为true 本小节是第一次学完 判断该用户对该课程下全部小节是否已学完
        Integer learnedSections = lesson.getLearnedSections();// 对课程已学的小节数
        allFinished = learnedSections + 1 >= sectionNum;// 所有课程已学完

        // 更新课表数据
        lessonService.lambdaUpdate()
                //.set(lesson.getStatus() == LessonStatus.NOT_BEGIN ,LearningLesson::getStatus,LessonStatus.LEARNING)
                .set(lesson.getLearnedSections() == 0, LearningLesson::getStatus, LessonStatus.LEARNING.getValue())
                .set(allFinished, LearningLesson::getStatus, LessonStatus.FINISHED)
                .set(LearningLesson::getLatestSectionId, dto.getSectionId())
                .set(LearningLesson::getLatestLearnTime, dto.getCommitTime())
                //.set(LearningLesson::getLearnedSections, lesson.getLearnedSections() + 1);
                .setSql("learned_sections = learned_sections + 1")
                .eq(LearningLesson::getId, lesson.getId())
                .update();

    }

    // 提交视频播放记录
    private boolean handleVideoRecord(Long userId, LearningRecordFormDTO dto) {
        // 查询旧的学习记录 learning_record userId lessonId SectionId
        LearningRecord learningRecord = queryOldRecord(dto.getLessonId(), dto.getSectionId());
        // LearningRecord learningRecord = this.lambdaQuery()
        //         .eq(LearningRecord::getLessonId, dto.getLessonId())
        //         .eq(LearningRecord::getSectionId, dto.getSectionId())
        //         .one();
        // 判断是否存在
        if (learningRecord == null) {
            // 不存在 新增学习记录
            LearningRecord record = BeanUtils.copyBean(dto, LearningRecord.class);
            record.setUserId(userId);
            // 保存学习记录 learning_record
            boolean result = this.save(record);
            if (!result) {
                throw new DbRuntimeException("新增学习记录失败");
            }
            return false;// 本小节没有学完
        }
        // 存在 更新学习记录 learning_record 更新字段 moment
        // 判断本小节是否是第一次学完 isFinish为true代表第一次学完
        boolean isFinished = !learningRecord.getFinished() && dto.getMoment() * 2 >= dto.getDuration();

        if (!isFinished) {
            LearningRecord record = new LearningRecord();
            record.setLessonId(dto.getLessonId());
            record.setMoment(dto.getMoment());
            record.setSectionId(dto.getSectionId());
            record.setFinished(learningRecord.getFinished());
            record.setId(learningRecord.getId());
            taskHandler.addLearningRecordTask(record);
            return false;
        }

        boolean result = this.lambdaUpdate()
                .set(LearningRecord::getMoment, dto.getMoment())
                .set(isFinished, LearningRecord::getFinished, true)
                .set(isFinished, LearningRecord::getFinishTime, dto.getCommitTime())
                .eq(LearningRecord::getId, learningRecord.getId())
                .update();
        if (!result) {
            throw new DbException("更新视频学习记录失败");
        }

        // 清理redis缓存
        taskHandler.cleanRecordCache(dto.getLessonId(), dto.getSectionId());
        return true;
    }

    private LearningRecord queryOldRecord(Long lessonId, Long sectionId) {
        // 查询缓存
        LearningRecord cache = taskHandler.readRecordCache(lessonId, sectionId);
        // 如果命中直接返回
        if (cache != null) {
            return cache;
        }
        // 如果未命中 查询db
        LearningRecord dbRecord = this.lambdaQuery()
                .eq(LearningRecord::getLessonId, lessonId)
                .eq(LearningRecord::getSectionId, sectionId)
                .one();
        if (dbRecord == null) {
            return null;
        }
        // 上面的判断 讲义上没写 不写会报空指针
        // 放入缓存
        taskHandler.writeRecordCache(dbRecord);
        return dbRecord;
    }

    // 处理考试记录
    private boolean handleExamRecord(Long userId, LearningRecordFormDTO dto) {
        // 将dto转换po
        LearningRecord record = BeanUtils.copyBean(dto, LearningRecord.class);
        record.setUserId(userId);
        record.setFinished(true);// 提交学习记录 代表本小节已学完
        record.setFinishTime(dto.getCommitTime());
        // 保存学习记录 learning_record
        boolean result = this.save(record);
        if (!result) {
            throw new DbRuntimeException("新增考试记录失败");
        }
        return true;
    }
}
